In machine construction, such shaft/hub connections are used in many ways for transmitting torques between the shaft and the hub. In addition to many requirements, the basic task of such types of connections is usually the transmission of high torques. The connections should thereby be as compact and light as possible and they should be mountable without extensive installation and adjustment work. On principle, all of the embodiments have in common that the torque transmission loads the shaft/hub connection. Dynamic loads are thereby usually higher than static loads.
Due to the fact that, for the most part, a conventional shaft/hub connection is not an interference fit, only a certain portion of the contact surfaces truly participates in torque transmission. This causes high stresses in the components, which must be compensated for or reduced by an appropriately long connection. However, the connection's enlarged length again causes larger radial run-out and reinforces a relative motion between shaft and hub, during which no transmission of torque occurs (the so-called play). The enlargement of radial run-out also leads to undesired noises and vibrations. A longer connection moreover facilitates sliding of the surfaces upon each other, which again promotes the formation of fretting corrosion. Finally, these effects lead to a reduction in the lifetime of the shaft/hub connection and consequently that of the entire system.
DE 198 36 259 A1 shows a tight shaft/hub connection in which, to reduce or prevent the undesired play, a radial pressing device presses the hub toward the rotational axis in such a manner, that the inner contour of the hub engages the shaft free of play. The disadvantage of this embodiment is the need for additional components, which is associated with higher space requirements and costs.
Clamping set connections, in which a clamping set is disposed between the shaft and the hub, are known for reducing or preventing the undesired play. Such a clamping set encompasses at least one element, by means of which the annular cross-section of the clamping set can be enlarged and the clamping set is thus, on the one hand, pressed against the jacket surface of the shaft and, on the other hand, against the inner surface of the hub bore and a connection, which is free of play, is created. DE 36 36 393 A1 describes such clamping sets, where the positive fit is achieved in that the shaft as well as the hub are provided with a longitudinal toothing and in that the clamping set encompasses, on the inside as well as on the outside, a longitudinal toothing, which in each case corresponds thereto. Due to the additional components, this embodiment is also associated with correspondingly higher costs having a relatively high space requirement. An additional time-intensive and thus cost-intensive operating step is required for the assembly of the clamping set.
EP 1 225 356 B1 describes a shaft/hub connection, where at least one of the components encompasses, in the area of the untrue entraining longitudinal section, at least two holding sections, which are angularly displaced to each other around the longitudinal axis. This can be achieved by means of torsion, for example, which runs across the entire length of the entraining longitudinal section but also by means of two non-twisted longitudinal sections, which are connected with each other via a connecting section and which are offset against each other. A plurality of connecting sections, each of which offsets longitudinal sections in stages or continually against each other, can also be used. It is disadvantageous that the production of the components is possible only with special and very expensive machines. The creation of a twisted inner contour, in particular, is difficult. The assembling or joining of such connections is only possibly with the application of a high axial force, because the sections deform in response to being joined to each other. A joining by hand is thus not possible.
The use of wedge-shaped elements, which are inserted between shaft and hub, is also well known. However, these lead to an eccentricity of the shaft and therefore to point contacts or relatively small contact surfaces between shaft and hub. However, this is oftentimes accepted because, as already described above, an increase or an even distribution of the contact surfaces within the entraining longitudinal section only seems to be possible with additional components and with considerably effort.
It is the objective of the present invention to create a shaft/hub connection with high functionality and lifetime. In response to a simple construction, the best possible transmission of the torque is to be achieved. The production of the components is to be simple and cost-efficient and the connection is to furthermore be capable of being assembled with little effort.